Apparatus for indicating the weight of a vessel&#39;s cargo.



D. MAGKAY. APPARATUS FOR INDIGATING THE WEIGHT 0F A VESSELS CARGO.

APPLICATION FILED 00T. 10, 1910.

Patented Sept. 12, 1911.

FIG-2.

v llll COLUMBIA PLANOGRAPH co.,wAsmNu'roN. n. c.

DONALD MACKAY, OF ALLOA, SCOTLAND.

APPARATUS FOR INDICATING THE WEIGHT OF A VESSELS CARGO.

Specification of Letters Patent.

Patented Sept. 12, 1911.

Application filed October l0, 1910. Serial No. 586,346.

To all whom it may concern:

Be it known that I, DONALD Mackay, a` subject of the King of Great Britain and Ireland, residing at Alloa, in the county of Clackmannan, Scotland, have invented new and useful Improvements in Apparatus for Indicating the Weight of a Vessels Cargo, of which the following is a specification.

My said invention relates t-o apparatus of the type comprising a. water-gage tube connected to the external water and a graduated scale having marked on it the draft and the corresponding deadweight for fresh and salt water respectively, and consists in providing a deadweight scale graduated for the range of densities from fresh to salt .water, and a cursor adapted to be employed in combination with such scale whereby the weight of cargo or the like placed on board ship, is obtained in a simple and expeditious manner.

In carrying out my invention the watergage tube is placed inside the ship at the middle, or center line, about amidships, and alongside the gage are placed scales of draft and deadweight. The water-gage extends in al vertical direction from below the light water-line, of the ship, to above the load water-line. The water-gage communicates at its lower end with the sea water by a pipe led through the sliips side, or bottom, and suitably controlled, and the top of the water-gage is open to the atmosphere. The sea water on being admitted flows in until it rises in the watergage` to the level of the water outside the ship, and thus indicates the mean draft of the ship. In close proximity to the watergage are placed the scales of draft and deadweight, hereinbefore referred to. By means of curves drawn between the extremes of fresh and salt water the deadweight at any density can be read off, in relation to the height of the water level in the tube.

In order that my said invention and the manner of performing the same may be properly understood I hereunto append a sheet of explanatory drawings to be hereinafter referred to in describing my inventori.

Figure l, is a transverse section of a. part` of a ship showing my improved apparatus fitted thereto. Fig. 2, is a view of the upper part of the indicator, drawn to an enlarged scale, and Fig. 3, is a plan.

In these drawings the same reference letters are used to mark the same or like parts wherever they are repeated.

As shown in Fig. l, of the drawings, the apparatus consists of a vertical glass tube A, placed near amidships at the center line of the ship and ext-ending from below the light water-line a, to above the load7 water-line .7). The lower end of the tube A, communicates with the water outside the ship through the valve B, and pipe C. A shut-o cock D, is provided to regulate the supply of water to the tube A, and a tap E, is also provided for drawing off water to be tested by a hydrometer. Beside the tube A, there is placed a board F, on which are drawn deadweight scales for salt and fresh water with curves G, drawn between them for intermediate densities of water. A cursor H, is provided in connection with the board F, and can be moved up and down to facilitate reading of the scales.

Fig. 2, of the drawings shows the top end of the indicator as it would appear when made for a vessel carrying 6,000 tons on a 20 foot draft. The column marked Salt 7 is the scale of tons deadweightfor salt water, and the column marked Fresh is the scale of tons deadweight for fresh water. The lines Gr, and the dotted lines G1, drawn between these two scales are curves of tons deadweight for all densities between salt water and fresh water. The vert-ical lines indicated by the figures .1, .2, .8, .4, .5, .0, .7, .8, and .9, are to enable particular scales to be read off. In this case they are shown at distances of .1, of the dierence in density between salt and fresh water. The cursor H, is also marked with the words Salt and Fresln and the figures .1, .2, .3, .4, .5, .6, .7, .8, and .9, to correspond with the words and figures at the top of the board F.

The apparatus is used as follows: The water having been admitted to the tube A, rises in that tube to the level of the water outside the ship, and the density of the water having been tested by a hydrometer, the pointer J, is then moved across the cursor H, to the point corresponding to the density which has been found. The cursor II, is now moved up, or down, until its top edge is at the water level, and then opposite the pointer J, can be read the number of tons deadweight on board the ship. The cursor H, is adjustably connected to the board F, by bolts K, Whose heads slide up and down in a groove L, and the bolts may be tightened to hold the cursor in any desired position.

M, is a scale of draft in feet and inches, While N, N, N, N, are marks corresponding to the usual freeboard marks on the outside of the ship.

The pointers l?, R, may be moved up and down so as to indicate the heights at which loading begins and ends.

lllhat I claim is:

l. In apparatus for indicating the Weight of cargo in a ship, in combination, a Water gage consisting of a tube open to the atv inosphere and communicating With the Water line below the light Water line of the ship, a scale of deadiveight positioned in juxtaposition to said tube, said scale being provided With curves corresponding to the range of densities from fresh Water to salt Water and an indicator operatively associated with said scale and said tube and adapted to indicate the dead- Weight corresponding to the density of the Water and the height of the Water in the tube.

2. In apparatus for indicating the Weight of cargo in a ship, in combination, a Water gage consisting of a tube open to the atmosphere and communicating with the Water line below the light Water line of the ship, a scale of deadweight positioned in juxtaposition to said tube, said scale being provided with curves corresponding to the range of densities from fresh Water to salt Water, an indicator operatively associated with said scale and said tube, and adapted to be moved relatively thereto into register With the upper level of the Water in the tube and movable means carried by said indicator to be moved into register With any one of the curves on the scale corresponding to the density of the Water Copies of this patent may be obtained for five cents each, by addressing the Cominssioner of Patents, Washington, D. C." 

